Role of the phosphoinositide 3-kinase pathway in mouse embryonic stem (ES) cells

2005 ◽  
Vol 33 (6) ◽  
pp. 1522-1525 ◽  
Author(s):  
K. Takahashi ◽  
M. Murakami ◽  
S. Yamanaka
Keyword(s):  
Es Cells ◽  
Mammalian Target Of Rapamycin ◽  
Embryonic Stem ◽  
Pi3k Pathway ◽  
Leukaemia Inhibitory Factor ◽  
Mouse Es Cells ◽  
Ras Family ◽  
Phosphoinositide 3 Kinase ◽  
Kinase Pathway

Mouse ES (embryonic stem) cells maintain pluripotency with robust proliferation in vitro. ES cells share some similarities with cancer cells, such as anchorage-independent growth, loss of contact inhibition and tumour formation. After differentiation, ES cells lose pluripotency and tumorigenicity. Recent studies showed that the PI3K (phosphoinositide 3-kinase) pathway is important for proliferation, survival and maintenance of pluripotency in ES cells. The PI3K pathway is activated by growth factors and cytokines including insulin and leukaemia inhibitory factor. In addition to these exogenous factors, the PI3K pathway is endogenously activated by the constitutively active Ras family protein ERas (ES cell-expressed Ras). The PI3K pathway utilizes multiple downstream effectors including mTOR (mammalian target of rapamycin), which we have shown to be essential for proliferation in mouse ES cells and early embryos.

scholarly journals DNA polymerase α interacts with H3-H4 and facilitates the transfer of parental histones to lagging strands

2020 ◽  
Vol 6 (35) ◽  
pp. eabb5820 ◽  
Author(s):  
Zhiming Li ◽  
Xu Hua ◽  
Albert Serra-Cardona ◽  
Xiaowei Xu ◽  
Songlin Gan ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Es Cells ◽  
Embryonic Stem ◽  
Endogenous Retroviruses ◽  
Histone Binding ◽  
Dna Polymerase Α ◽  
Mouse Es Cells ◽  
Dna Strands ◽  
Histone Deposition

How parental histones, the carriers of epigenetic modifications, are deposited onto replicating DNA remains poorly understood. Here, we describe the eSPAN method (enrichment and sequencing of protein-associated nascent DNA) in mouse embryonic stem (ES) cells and use it to detect histone deposition onto replicating DNA strands with a relatively small number of cells. We show that DNA polymerase α (Pol α), which synthesizes short primers for DNA synthesis, binds histone H3-H4 preferentially. A Pol α mutant defective in histone binding in vitro impairs the transfer of parental H3-H4 to lagging strands in both yeast and mouse ES cells. Last, dysregulation of both coding genes and noncoding endogenous retroviruses is detected in mutant ES cells defective in parental histone transfer. Together, we report an efficient eSPAN method for analysis of DNA replication–linked processes in mouse ES cells and reveal the mechanism of Pol α in parental histone transfer.

182. NOVEL SIGNALLING IN MOUSE EMBRYONIC STEM CELLS GENERATES PRIMITIVE ECTODERM-LIKE CELLS

2009 ◽  
Vol 21 (9) ◽  
pp. 100
Author(s):  
M. B. Morris ◽  
N. Hamra ◽  
A. C. Lonic ◽  
F. Felquer
Keyword(s):  
Es Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
Leukaemia Inhibitory Factor ◽  
Signalling Pathways ◽  
Specific Cell ◽  
Self Renewal ◽  
Mouse Es Cells ◽  
Homogeneous Production ◽  
Extracellular Molecules

The phenotypic status of embryonic stem (ES) cells is controlled in part by signalling pathways which translate inputs mediated by extracellular molecules. An important extracellular protagonist in mouse ES cells is LIF (leukaemia inhibitory factor) which interacts with the gp130–LIFR receptor complex to activate a number of downstream signalling pathways, including the STAT3, MEK/ERK and PI3K/Akt. These pathways, together with others, interact in complex and sometimes competing ways to generate the well-known characteristics of mouse ES cells of self-renewal, high rates of proliferation, and pluripotence. The addition of a second molecule, L-proline, to the extracellular environment alters the pluripotent status of mouse ES cells, converting them to a second pluripotent population equivalent to the primitive ectoderm of the pre-gastrulating embryo. This conversion, from ES cells to primitive ectoderm-like cells, primes the latter for directed differentiation to specific cell types (1). Here we show, using inhibitor studies and kinome array analysis, that this small molecule appears to work by (i) changing the balance in activity of signalling pathways already stimulated by LIF and (ii) activating additional signalling pathways. Specifically, L-proline rapidly further activates the LIF-stimulated MEK/ERK pathway, tipping the balance in favour of primitive-ectoderm formation and away from ES-cell self-renewal sustained by LIF-mediated activation of the STAT3 pathway. In addition, L-proline rapidly stimulates other pathways including p38, mTOR and PI3K/Akt each of which contributes, to a greater or lesser extent, to the conversion to primitive ectoderm-like cells. These results indicate that (i) L-proline acts in novel ways to stimulate embryo-like developmental progression in ES cells and (ii) through the addition of small, nontoxic activators and inhibitors of signalling pathways, the differentiation of pluripotent ES cells might be controlled sufficiently well for the homogeneous production of specific cell types suitable for use in animal models of human disease.

Study of the C60 Fullerene on Differentiation of Mouse Embryonic Stem Cells

2012 ◽  
Vol 529-530 ◽  
pp. 385-390
Author(s):  
Koichi Imai ◽  
Fumio Watari ◽  
Kazuaki Nakamura ◽  
Akito Tanoue
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Experimental Method ◽  
Es Cells ◽  
Embryonic Stem ◽  
Future Generations ◽  
C60 Fullerene ◽  
Biological Safety ◽  
Mouse Es Cells

The risks of nanomaterials for future generations should be elucidated. Thus, it is important to establish an experimental method to accurately examine embryotoxicity. We have conducted anin vitroembryotoxicity test with mouse ES cells to examine the embryotoxicities of various nanomaterials. In this study, the C60 fullerene did not influence the differentiation of ES-D3 cells and "non embryotoxicity". In the future, the biological safety should be comprehensively examined by improving dispersion in medium.

220 NONHUMAN PRIMATE EMBRYONIC STEM CELLS SIMILAR TO THE BIOLOGICAL PROPERTIES OF MOUSE EMBRYONIC STEM CELLS

2012 ◽  
Vol 24 (1) ◽  
pp. 222
Author(s):  
A. Kusanagi ◽  
J. Yamasaki ◽  
C. Iwatani ◽  
H. Tsuchiya ◽  
R. Torii
Keyword(s):  
Nonhuman Primate ◽  
Cynomolgus Monkey ◽  
Es Cells ◽  
Embryonic Stem ◽  
Biological Properties ◽  
Es Cell ◽  
Mouse Es Cells ◽  
Mouse Es Cell

Human and mouse embryonic stem (ES) cells are derived from the inner cell mass of preimplantation blastocysts and human ES cells were long thought to be equivalent to mouse ES cells, despite clear morphological difference and different signalling pathways to maintain their pluripotency between these two ES cell types. Mouse ES cells depend on leukemia inhibitory factor (LIF) and bone morphogenic protein 4 (BMP4) signalling, whereas their human counterparts rely on basic fibroblast growth factor (bFGF) and activin A signalling. The biggest difference of two ES cells is the ability of chimera formation and mouse ES cells can contribute chimera but primate ES cells fails to do that. Monkey ES cells in primates only can be tested for chimera formation in vivo due to the ethical issue and cynomolgus monkey is the most common nonhuman primate to be used for the safety study of drug discoveries. The objective of this study was to develop novel cynomolgus monkey ES cells that have similar biological properties with mouse ES cell and our ultimate goal is to establish germline competent nonhuman primate ES cells. Ovarian stimulation and oocyte collection were carried out for the derivation of ES cells as previously described by Torii et al. Briefly, GnRH (0.9 mg/head) was administered to cynomolgus monkey and two weeks later, a micro infusion pump (iPRECIO™, Primetech Corp) contains FSH was implanted subcutaneously. Follicular aspiration was then performed 40 h after hCG injection and metaphase II oocytes were fertilized by intracytoplasmic sperm injection (ICSI). Cynomolgus monkey ES cells were then established under mouse ES cell conditions such as LIF/STAT signalling and a dome tree-dimensional (3D) morphology nonhuman primate ES cells were selected. On the other hands, ES cells that were established with the presence of basic FGF showed conventional layer-type morphology. Dome-type ES cells express pluripotent transcriptional factors such as Oct-3/4, Nonog and Sox2 as same as layer-type ES cells and both ES lines were capable of multilineage differentiations in vitro after embryoid body formation. Dome-type nonhuman ES cells can also form teratomas and differentiated into all three germ layers when grafted into immunodeficiency mice. For fluorescent gene delivery to nonhuman primate ES cells, feeder-free condition was applied and CAG-GFP vector was transfected into ES cells using Neon electroporation system (Invitrogen Inc.) for the tracing ES cells in the transplantation study. In this study, we have established dome-type ES cell lines that similar to mouse ES cells in morphology and signalling pathway. Dome-type nonhuman primate ES cells express pluripotent gene markers and prove their pluripotency both of in vitro and in vivo, in addition, these modifications would be important to create germline competent ES cells.

Establishment of germ-line-competent embryonic stem (ES) cells using differentiation inhibiting activity

Development ◽  
1990 ◽  
Vol 110 (4) ◽  
pp. 1341-1348 ◽  
Author(s):  
J. Nichols ◽  
E.P. Evans ◽  
A.G. Smith
Keyword(s):  
Germ Line ◽  
Es Cells ◽  
Embryonic Stem ◽  
Leukaemia Inhibitory Factor ◽  
Inhibiting Activity ◽  
Es Cell ◽  
Essential Function ◽  
Germ Line Transmission

The regulatory factor Differentiation Inhibiting Activity/Leukaemia Inhibitory Factor (DIA/LIF) suppresses the differentiation of cultured embryonic stem (ES) cells. In the present study, it is shown that ES cell lines can be derived and maintained in the absence of feeder layers using medium supplemented with purified DIA/LIF. These cells can differentiate normally in vitro and in vivo and they retain the capacity for germ-line transmission. DIA/LIF therefore fulfils the essential function of feeders in the isolation of pluripotential stem cells.

WNT3A signalling pathway in buffalo (Bubalus bubalis) embryonic stem cells

2014 ◽  
Vol 26 (4) ◽  
pp. 551 ◽  
Author(s):  
Mohammad Zandi ◽  
Musharifa Muzaffar ◽  
Syed Mohmad Shah ◽  
Ramakant Kaushik ◽  
Manoj Kumar Singh ◽  
...  
Keyword(s):  
Es Cells ◽  
Embryonic Stem ◽  
Polymerase Chain Reaction Analysis ◽  
Bubalus Bubalis ◽  
Embryoid Bodies ◽  
Signalling Pathway ◽  
Leukaemia Inhibitory Factor ◽  
In Vitro Fertilisation ◽  
Canonical Wnt

The aim of this study was to investigate the transcriptional profile and role of WNT3A signalling in maintaining buffalo embryonic stem (ES) cells in a pluripotent state and in the induction of their differentiation. ES cells were derived from embryos produced by in vitro fertilisation (iESC), parthenogenesis (pESC) and hand-made cloning (cESC). The expression of WNT3A, its receptors and intermediate signalling pathways were found to be conserved in ES cells derived from the three different sources. WNT3A was expressed in ES cells but not in embryoid bodies derived from iESC or in buffalo fetal fibroblast cells. It was revealed by real-time polymerase chain reaction analysis that following supplementation of culture medium with WNT3A (100, 200 or 400 ng mL–1) a significant increase (P < 0.05) was observed in the expression level of β-CATENIN, which indicated the activation of the canonical WNT pathway. WNT3A, in combination with exogenous fibroblast growth factor-2 and leukaemia inhibitory factor, induced proliferation of undifferentiated ES cells. Differentiation studies showed that WNT3A caused formation of scaffold-like structures and inhibition of differentiation into neuron-like cells. In conclusion, the WNT3A signalling pathway is necessary both for maintaining undifferentiated buffalo ES cells as well as for directing their differentiation.

LIF: a molecule with divergent actions on myeloid leukaemic cells and embryonic stem cells

1989 ◽  
Vol 1 (4) ◽  
pp. 281 ◽  
Author(s):  
NM Gough ◽  
RL Williams ◽  
DJ Hilton ◽  
S Pease ◽  
TA Willson ◽  
...  
Keyword(s):  
Embryonal Carcinoma ◽  
Es Cells ◽  
Embryonic Stem ◽  
Leukaemia Inhibitory Factor ◽  
Genetic Manipulations ◽  
Leukaemic Cells ◽  
Ec Cells ◽  
Necessary And Sufficient ◽  
Cell Conditioned Medium

We have previously characterized, purified and cloned a novel murine and human regulator [leukaemia inhibitory factor, LIF] which induces the differentiation of certain murine and human myeloid leukaemic cells. Recently we have shown that there are specific LIF receptors on murine embryonic stem [ES] and embryonal carcinoma [EC] cells and that purified recombinant LIF can substitute for feeder cells and crude sources of differentiation inhibiting activity [DIA] [such as BRL-cell-conditioned medium] in the maintenance of ES cells in a pluripotential state in vitro. Furthermore, ES cells maintained in culture in recombinant LIF for a prolonged period can give rise to germline chimaeric mice. Thus, based on a number of biochemical and biological similarities, it is likely that LIF and DIA are the same molecule. The identification of LIF as a molecule, necessary and sufficient for the maintenance of ES cells in culture, should have a profound impact on the use of these cells for genetic manipulations.

scholarly journals Conserved and divergent features of DNA methylation in embryonic stem cell-derived neurons

2020 ◽  
Author(s):  
Sally Martin ◽  
Daniel Poppe ◽  
Nelly Olova ◽  
Conor O’Leary ◽  
Elena Ivanova ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Es Cells ◽  
Embryonic Stem ◽  
Nuclear Lamina ◽  
Neuronal Maturation ◽  
Neuronal Marker ◽  
Mouse Es Cells ◽  
Primary Mouse

AbstractDNA methylation functions in genome regulation and is implicated in neuronal maturation. Early post-natal accumulation of atypical non-CG methylation (mCH) occurs in neurons of mice and humans, but its precise function remains unknown. Here we investigate mCH deposition in neurons derived from mouse ES-cells in vitro and in cultured primary mouse neurons. We find that both acquire comparable levels of mCH over a similar period as in vivo. In vitro mCH deposition occurs concurrently with a transient increase in Dnmt3a expression, is preceded by expression of the post-mitotic neuronal marker Rbfox3 (NeuN) and is enriched at the nuclear lamina. Despite these similarities, whole genome bisulfite sequencing reveals that mCH patterning in mESC-derived neurons partially differs from in vivo. mESC-derived neurons therefore represent a valuable model system for analyzing the mechanisms and functional consequences of correct and aberrantly deposited CG and non-CG methylation in neuronal maturation.

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